Watercraft having a wind-powered drive unit

ABSTRACT

A watercraft incorporating a wind propulsion system, revealing a main mast and an auxiliary mast. According to the invention, provision is made for a length of the auxiliary mast between a flexible joint and the deck as well as an included angle α from the main mast and deck capable of being locked in position on variable lines.

The invention relates to a watercraft incorporating a hull, a main mast and an auxiliary mast.

Since time immemorial efforts have focused on improving the propulsion system of watercraft, enhancing efficiency combined with reduced cost and meanwhile achieving greater compatibility with the environment.

In most cases, increasing performance proceeds at the expense of economy. Hitherto, use has hitherto been made, above all for the transportation of cargo by sea, of what are to some extent container ships posing a heavy burden. The transportation of freight by wind-powered watercraft no longer enters into consideration to any appreciable extent owing to the vessels being heavily dependent on external factors such as wind and currents, this not only involving exceedingly longer, but also less easily calculable travel times compared to engine-powered vessels.

What is more, common sail designs for use on cargo and container ships are not a viable economic solution on account of the space required for masts and sail areas.

A ship's mast is defined as being a completely or approximately vertical construction built from wood, metal or other solid materials. Originally, masts were employed solely for supporting sails and appurtenant fittings required for their operation. Later they additionally served as a lookout and support for various marine components, as for instance radio antennas, radar reflectors, position lights, etc.

The majority of sports boats and yachts are sloop-rigged and are thus constructed with one single mast to which two triangular-shaped sails are attached. In addition, there are ketch-, yawl- and schooner-rigged yachts, though these are rarely built today.

In ancient times, masts were made solely of wood. Today, they are primarily manufactured from aluminium, while regatta sail boats are usually built with masts made from a carbon-fibre composition or CFC. Up to the beginning of the 20th century wooden masts were solid constructions. Afterwards, hollow wooden profiles began to dominate. Aluminium and CFC masts are always constructed as hollow profiles. Apart from imparting better stability, this makes it possible to stow and protect halyards and cables inside the mast.

Profiled masts exercise an advantageous streamlined effect on account of their special cross-section; to some extent they also provide extra “sail area”.

Innovations such as lattice-type or A-shaped masts set up without shrouds failed to assert themselves either for cruisers or regatta sail boats and remained restricted to extremely isolated uses by self-builders.

Normally the mast is supported in the mast track on the keel and is led through the deck. To prevent water from penetrating, the orifice is closed off by a mast collar. Alternatively, a mast can be made to stand on the deck but then needs to be supported from underneath on the keel so as to prevent the deck from sagging under the loads exerted. Normally, masts are supported by standing rigging; free-standing masts are usually found on small dinghies such as the laser dinghy (one exception in this case being the Maltese Falcon grand yacht).

On known wind-powered watercraft a boom is attached to the mast, the main sail then being tensioned between the boom and the mast. Formerly the main sail was attached to the mast by a thin cord or inserted in the mast slot with the bolt rope. Today, the sail is secured inside a profile groove with mast sliders or via ball-bearing-mounted mast slides.

In early times, masts merely consisted of a straight-grown tree trunk, this type of mast being known as a pole mast.

As early as the 16th century the masts were composed of several pieces of wood in cross-section, being held together with woolding rope and iron rings (constructed masts).

To attain a larger height, the lower mast is extended using top masts enabling a total length of up to 60 metres to be reached measured from the keel. Such masts came to be described as added or divided masts.

The forces of the sails acting on the mast construction are induced in the hull structure by standing and running rigging to the fore and aft (rear) by means of stays and to the sides by shrouds or guys.

A feature shared by the structures described is that the length of the mast exceeds the length of the ship. This, together with the mounting method and position of the mast on deck, make the mast not all that easy to lower, especially on larger watercraft. Hence, on larger vessels in particular, the mast is nearly always in the raised position. Lowering of the mast with only one person on board is virtually ruled out. Even this were possible using suitable aids as described in GB 2 334 238 A for example, a lowered mast would require a great deal of space on board quite apart from causing heavy logistic restrictions.

Add to that, the mounting method and position claims a high amount of space which is then no longer available for transporting cargo or for the designing generously laid-out cabins.

The purpose of the invention is to provide a watercraft designed to bring about eco-friendly and enhanced efficiency compared to conventional types, one of the main objectives being to increase speed with equal or even reduced fuel consumption as far as possible without sacrificing space on deck.

This task is solved by a watercraft incorporating features of the various independent claims.

Thus, a primary aspect of the invention relates to a watercraft revealing a hull, a main mast and an auxiliary mast, the latter arranged on the main mast via a flexible joint. The auxiliary mast spreads itself out further from an area of the deck in the bow of the watercraft. The main mast, on the other hand, is connected to the hull of the watercraft on the starboard side and portside. The material and outer form as well as the arrangement of the main and/or auxiliary mast below or on deck correspond to the design favoured and described in the introductory section above.

According to the invention provision is made for a length of the auxiliary mast between the flexible joint and the area of the bow as well as an included angle enclosed by the main mast and deck capable of being locked in position along variable lines.

By means of the flexible joint, force is transmitted from the main mast onto the auxiliary mast. The reduction in length on the auxiliary mast facilitates lowering the main mast. In addition, the embodiment of the invention makes it possible to erect a main mast at a significantly different and adjustable angle α of 90° a between the main mast and deck. Accordingly, this angle can be adapted to the prevailing wind and water conditions (shallow water, waves) so as to cater for improved handling applied to speed and stability, geared to individual requirements.

A special advantage further distinguishing the design of the propulsion according to the invention is that the main mast can be folded completely without the necessity of loosening the connections. Apart from benefits gained thereby in handling the mast, this means that there are no accessories or open ends requiring to be stowed away or secured. In addition, the design remains sturdy no matter in what state, fully raised or lowered including all stages in between. Instability of the watercraft is thus evaded whenever connections need to be loosened.

The length of the auxiliary mast and/or the included angle α between the main mast and deck is—preferentially—capable of being locked in position to the widest extent possible between a minimum position (mast lowered) and a maximum position (mast raised) on infinitely variable or in stages. The minimum position lies within the range of 0 to 10° referencing to angle α, while the maximum position lies within the range of 45 to 90° referencing to the included angle α. This makes it possible to vary the mast in more than two positions, thus catering for greater freedom on the part of the user when utilising the wind power.

An advantage is that the auxiliary mast extends from an orifice in the deck or hull of the watercraft and is in particular designed so as to enable the mast to be retracted, at least to partial extent, in the bow. This serves to reduce the length of the auxiliary mast by embedding it in the bow, i.e. below deck. Accordingly, the auxiliary mast claims no space on deck. The propulsion system designed according to the invention also makes retrofitting particularly easy on existing watercraft. The design is also ideally suitable for one-piece auxiliary masts as it facilitates length reduction on these, too.

Where the orifice for the auxiliary mast is located in the hull, it is preferable for the auxiliary mast to be conducted over the deck in the direction of the waterline and via an orifice above the waterline from the outside into the hull of the watercraft.

In a preferred embodiment of the invention compared to that previously described, provision is made for flexibility as applied to the auxiliary mast. This makes it possible when retracting the auxiliary mast inside the bow of the watercraft to adapt it to an inner form of the hull. Thus, also on flatter hulls—as encountered for instance on dinghies or centre boards—the length can be reduced by retracting the auxiliary mast into the hull. In addition, a flexible auxiliary mast reveals advantages as regards distribution of force as well as imparting greater stability compared to rigid auxiliary masts of the same diameter.

The term flexible in this context means that when the auxiliary mast is erected vertically, the weight of an upper section is sufficient on its own to bend the mast. The auxiliary mast reveals a favourable elastic modulus of less than 15 GPa. Preferably, the elastic modulus extends from 1 to 10, beneficially in a range from 1 to 6.

Alternatively or additionally, the auxiliary mast reveals a curvature or bend, preferably over its entire length. This embodiment reveals the same advantages as a flexible embodiment of the auxiliary mast. Particularly advantageous are the features combining flexibility and curvature of the auxiliary mast with one another owing to this enhancing the positive characteristics of the individual features beyond the sum total of individual effects, especially as regards increased stability as well as adaptation to the hull.

In another preferred embodiment provision is made for the auxiliary mast to incorporate tubular components arranged coaxially to one another in one section, with one length of the coaxial section capable of being locked in position on variable lines and the length of the section behaving indirectly proportional to the length of the auxiliary mast. This embodiment facilitates a reduction in length, alternatively or additionally to the retraction in the bow as described above. In this case, the auxiliary mast is a multiple-component structure with at least two components essentially revealing a circular cross-section and being hollow, at least section-wise. The two parts are arranged towards each other so as to overlap at least one part of the hollow sections in such a way that that part revealing a larger cross-section encloses a periphery of the other part; hence the two parts are arranged coaxially to one another.

In a preferred embodiment of the invention provision is made for the main mast to incorporate what are essentially two elongated components connected to the hull or deck of the watercraft at one initial end on the starboard side or portside and firmly bonded together, in particular materially-bonded, at another end. This embodiment serves to stabilise the main mast while facilitating an inclined position towards the deck even under load. Also especially preferred is the fact that the main mast reveals no further elongated components from the deck or hull of the watercraft. In particular, the main mast desirably reveals no middle section arranged in a central position relating to the width of the deck. This provides better utilisation of the deck for loads and cabin facilities. In addition, when lowering the main mast, this does not come to rest in a central area. In particular, it is not conducted over a cabin or the area of the steering helm, but comes to rest in an area adjacent to the deck periphery or is accommodated above deck, stabilised for instance by the auxiliary mast.

Especially beneficial in that respect is the fact that the two bonded components of the main mast on the starboard side and portside reveal a curvature, at least section-wise. Preferentially, the shape and height of the main mast correspond essentially to the form of an inner contour of the deck periphery. The term essential in this context means that the absolute dimensions, while not necessarily being fully compatible, nevertheless ensure that the lowered mast runs parallel to the inner periphery of the deck as closely as possible.

If the watercraft is essentially a wind-powered yacht, it is preferable for the connecting bond on the starboard side or portside between the components of the main mast and the hull or deck of the watercraft not to be arranged amidships but rather on the stern side, especially in the area of the stern of the watercraft. Conversely, in the embodiment of the watercraft designed in the form of a cargo or container ship, the connecting bonds mentioned above are preferably arranged by and large amidships. In that case, setting is effected “essentially” in a range of +/−30%, in particular +/−20% and preferably +/−10%, proceeding in each case from a midship line running perpendicular to the connection line between the bow and stern.

Also preferential is the inclusion of the auxiliary mast with main mast at an angle β in the range of 0 to 90°. This angle varies according to the position of the auxiliary and main mast. The angle β between the main and auxiliary mast is determined by the length of the auxiliary mast, this also applying to the angle α between the main mast and the deck.

As described above, the length of the auxiliary mast can be locked in at least two positions, i.e. a minimum length and a maximum length of the auxiliary mast. In the maximum-length position, the preferred angle β is 25 to 75, especially favoured in the range of 50 to 70°,

An advantage is that the main mast and a surface of the deck include an angle of less than 90°. In the maximum position assumed by the auxiliary mast this angle preferably lies within the range of 60 to 70°. The above-mentioned term “surface of the deck” is intended to imply a constructed or physical surface denoting the intersections of a plumb line applied to the connection bond of the main mast with the deck or the deck periphery of the watercraft and the plumb line, proceeding from the connection bond of the main and auxiliary mast on the deck. This brings about a tilt on the main mask towards the bow which in turn leads to a transfer of weight, this serving to stabilise the watercraft.

This shows that, as a result of the described tilt angle, an area utilised by the wind is maximised compared to other tilt angles of the main mast.

For powering the watercraft by wind, this further reveals at least one sail. Preferably this is arranged by means of a connecting device in the bow of the watercraft, on the hull and/or deck and is joined to the main mast on a side facing away from the connecting device. This allows the sail to be tensioned between the deck and main mast. This obviates the need for an additional component such as a boom for fastening or aligning the sail. As a result if this embodiment the utilisable sail area is maximised.

The said connecting device preferably assumes the form of a rope winch and/or suitably equipped means designed to provide tensioning of the sail cloth or to vary the same, more especially to adapt the sail area to the prevailing wind conditions so that the sail can be set directly or indirectly accordingly by means of the said connecting device: bulged, very tight i.e. virtually flat, gathered or drawn-in and all other variations in-between.

Particularly advantageous is the fact that the sail reveals what is essentially a trigonal or trapezoidal area and is joined, directly or indirectly, to the main mast at one corner and on one side, by means of the connecting device, This embodiment ensures that the sail area is utilised on optimum lines.

Another preference is that the watercraft reveals several neighbouring sails and that sails adjacent to each other form an overlap not exceeding a 20° area percentage referencing to the sail area with the sail in hoisted state. This is preferably attained by an appropriate area shape of the adjacent sails and/or by the angle α between the area of the deck and the main mast,

Preferable in particular is a plurality of sails equally arranged on both sides of the auxiliary mast, i.e. starboard side and portside.

A further aspect of the invention relates to an engine-powered watercraft, in particular a container ship in one of the above-mentioned embodiments. The combination of effective wind-power utilisation in conjunction with the engine propulsion system not only increases the efficiency of the vessels, but also reduces fuel costs and emission. The embodiment according the invention makes it possible to save on ongoing operating costs, especially in the sector of commercial shipping. As a result of the three-piece mast design, the skipper is able to raise the mast without much effort, to set the sails and utilise these to add support to mobility, then to lower the same on waterways or when entering a port.

Existing container ships, in particular, can be retrofitted with a wind propulsion system without having to be equipped with midship mast structures which would otherwise involve dismantling the command bridge or ship's cabin. Another advantage gained from the propulsion system designed according to the invention is that no loading space is sacrificed. Particularly advantageous are the engine-powered vessels, especially cargo or container ships designed with the propulsion system evolved according to the invention, for transporting cargoes on narrow, shallow and/or busy waterways such as straits or canals owing to the drive system allowing the engine to be switched off, thus relieving what are already seriously affected eco systems in such regions.

Unless indicated otherwise in the individual cases specified, the described embodiments can be beneficially combined with one another.

The invention will now be described in closer detail by way of example using figures.

Figures used to describe the invention:

FIG. 1 Schematic top view of a watercraft according to a preferred embodiment of the invention.

FIG. 2 Schematic side view of a watercraft according to a preferred embodiment of the invention.

FIG. 3 Schematic side view of a watercraft according to another embodiment of the invention designed as a yacht.

FIGS. 1 and 2 each show a schematic view of a watercraft 10 according to the invention in a preferred embodiment. FIG. 1 shows the watercraft 10 as a top view, FIG. 2 as a side view.

The watercraft can be designed as a yacht, especially as an engine-powered or sail yacht, further as a dinghy, a keel boat, a keel and centreboard yacht and as a cargo or container ship.

The watercraft 10 comprises a hull 5 on which a deck 12 is set up. Arranged on the deck 12 of the watercraft 10 is a mast structure for attaching sails 4. This comprises a main mast 1 and an auxiliary mast 2.

The main mast 1 is designed as a tiltable component in the extension direction of the hull 5 towards the bow 6 and is capable of being locked in at least two positions, a maximum position (shown in FIG. 1) and a minimum position (mast lowered). The main mast 1 preferably comprises two mast components 1 a and 1 b essentially elongated. Preferably, the main mast 1 reveals no further elongated mast components as is apparent in FIGS. 1 and 2. In this case the two mast components 1 a and 1 b are firmly joined together at one end (materially and/or frictionally bonded). At another end one mast component 1 a on the starboard side is joined to the hull 5 and/or the deck 12 by means of a connecting device, the other mast component 1 b on the portside being joined to the hull 5 and/or the deck 12 by means of a connecting device 3. The connecting device 3 is preferably rotatable, designed for example as an articulated joint.

As an alternative to the two-piece embodiment of the main mast 1, the main mast reveals an additional elongated mast component (not illustrated) which is then arranged centrally. In this embodiment the two components 1 a and 1 b are arranged on a further component. This embodiment allows a compact arrangement to be applied to the main mast 1. Nevertheless, it claims more space when lowering or tilting the main mast in a central area of the deck.

The main mast 1 reveals a connection 8 with an auxiliary mast 2 in an end section facing away from the connecting device. This joint 8 is rigid or flexible, in particular rotatable.

The auxiliary mast 2 is arranged at an end facing away from the connection 8 in the bow of the watercraft on the deck 12 or on the hull 5. The auxiliary mast 2 is distinguished by revealing a variable length L. This length L corresponds to a spacing distance between the connection 8 of the main and auxiliary mast 2 and the deck 12 or hull 5 at the point where the auxiliary mast 2 it is assembled with it. The variability can be attained by the embodiment of the auxiliary mast 2 itself and/or by the possibility of retracting the auxiliary mast 2 through an orifice in the deck 12 or inside location of the hull 5, i.e. below the deck of the watercraft 10.

On the first-mentioned version the auxiliary mast 2 reveals articulated sections which allow the auxiliary mast 2 to be folded. Alternatively or additionally, it is constructed from several tubular sub-components, at least section-wise, in which case adjacent ones or at least those relevantly located form a coaxial overlap. This coaxial arrangement allows adjacent sub-components to be placed against each another and retracted into one another.

The auxiliary mast 2 is preferably designed on flexible lines. This is advantageous when retracting the auxiliary mast 2 below the deck 12 as illustrated especially in FIG. 1.

The watercraft 10 also possesses at least one sail 4 which preferably reveals a sail cloth having a trapezoidal or trigonal shape. The sail 4 is arranged—directly or indirectly on deck—on the main mast 1, preferably on one of the sub-components 1 a or 1 b.

Optionally installed in the keel of the watercraft 10 is an engine forming a link to the propeller connected to the hull.

REFERENCE LIST

-   1. Main mast -   1 a, 1 b Sub-components -   2 Auxiliary mast -   3 Connection; joint -   4 Sail -   5 Hull -   6 Bow -   7 Keel -   8 Connection—main mast/auxiliary mast -   9 Connecting device—sail deck/hull; rope winch -   10 Watercraft -   12 Deck -   L Length 

1. A watercraft revealing a hull, a main mast and an auxiliary mast arranged on the main mast by means of a flexible joint and an auxiliary mast extending from an area of the deck in the bow of the watercraft, whereby the main mast is connected to the hull of the watercraft on the starboard side and port side, wherein a length of the auxiliary mast between the flexible joint and the deck as well as an angle α between the main mast and the deck is capable of being locked in various positions.
 2. The watercraft according to claim 1, wherein the auxiliary mast reveals flexibility, preferably having an elastic modulus of less than 15 GPa, the elastic modulus preferably is in a range from 1 to 10, beneficially in a range from 1 to
 6. 3. The watercraft according to claim 1, wherein the auxiliary mast extends from an orifice in the deck or in the hull and designed to be at least partially retractable in the hull.
 4. The watercraft according to claim 1, wherein the auxiliary mast comprises tubular components arranged coaxially to one another in one section with one length of the coaxial section capable of being locked in position on various positions and the length of the section is indirectly proportional to the length of the auxiliary mast.
 5. The watercraft according to claim 1, wherein the main mast comprises components, which show essentially elongates shape connected to the hull or deck of the watercraft at one initial end on the starboard side and portside and firmly bonded together, in particular materially-bonded, at another end.
 6. The watercraft according to claim 1, wherein an angle β between the auxiliary mast and the main mast is in the range of 0 to 90°.
 7. The watercraft according to claim 1, wherein the angle α between the main mast and the deck less than 90°.
 8. The watercraft according to claim 1, revealing further at least one sail fastened by means of a connecting device to the hull and/or deck, wherein the sail is joined to the main mast on a side facing away from the connecting device.
 9. The watercraft according to claim 8, wherein the sail is essentially trigonal or trapezoidal shaped and which is joined, directly or indirectly, to the main mast on one side opposite the corner by means of the connecting device.
 10. The watercraft according to claim 1, wherein the watercraft reveals a plurality of sails arranged adjacent to each other and/or on both sides of the auxiliary mast, wherein adjacent sails revealing an overlap not exceeding a 20° area percentage, referencing to the sail area with the sail in the hoisted state. 